Project description:Transcription is a major obstacle for replication fork progression and a cause of genome instability. Such instability increases in mutants with a suboptimal assembly of the nascent messenger ribonucleo-protein particle (mRNP), as THO/TREX and some heterogeneous nuclear ribonucleoproteins (hnRNPs) mutants. Here we show that yeast npl3∆ cells show genome-wide replication obstacles as determined by accumulation of the Rrm3 helicase. Such obstacles preferentially occur at long and highly expressed genes, to which Npl3 is preferentially bound in wild-type cells.
Project description:Transcription is a major obstacle for replication fork progression and a cause of genome instability. Such instability increases in mutants with a suboptimal assembly of the nascent messenger ribonucleo-protein particle (mRNP), as THO/TREX and some heterogeneous nuclear ribonucleoproteins (hnRNPs) mutants. Here we show that yeast npl3M-bM-^HM-^F cells show genome-wide replication obstacles as determined by accumulation of the Rrm3 helicase. Such obstacles preferentially occur at long and highly expressed genes, to which Npl3 is preferentially bound in wild-type cells. ChIP-chip studies were perfomed with antibodies against Myc-tagged Npl3 protein in wild-type cells of the yeast S. Cerevisiae, as well as Flag-tagged Rrm3 protein in both wild-type and npl3M-bM-^HM-^F cells.
Project description:Transcription is a major contributor to genome instability.A main cause of transcription-associated instability relies on the capacity of transcription to stall replication. Such genome instability is increased in RNAPII mutants. ChIP-chips performed in asynchronous cultures showed an increase of the Rrm3 binding signal all over the genome in rpb1-1 compared to wild-type.
Project description:Transcription is a major obstacle for replication fork progression and a cause of genome instability. Such instability increases in mutants with a suboptimal assembly of the nascent messenger ribonucleo-protein particle (mRNP), as THO/TREX and the NPC-associated THSC/TREX-2 complex. Here we show that yeast sac3∆ and thp1∆ cells accumulate genome-wide replication obstacles as determined by the distribution of the Rrm3 helicase. Such obstacles preferentially occur at long and highly expressed genes, to which Sac3 and its interacting partner Thp1 are preferentially bound in wild-type cells.
Project description:Transcription is a major contributor to genome instability.A main cause of transcription-associated instability relies on the capacity of transcription to stall replication. Such genome instability is increased in RNAPII mutants. ChIP-chips performed in asynchronous cultures showed an increase of the Rrm3 binding signal all over the genome in rpb1-1 compared to wild-type. ChIP-chip studies were perfomed with antibody against Flag-tagged Rrm3 protein in both wild-type and rpb1-1 cells.
Project description:Transcription is a major obstacle for replication fork progression and a cause of genome instability. Yra1 is an essential nuclear factor of the evolutionarily conserved family of hnRNP-like export factors that when overexpressed impairs mRNA export and cell growth. Through this ChIP-chip analysis it is shown that Yra1 binds to active chromatin and is enriched at telomeres when it is overexpressed, in agreement with a possible role of this mRNP factor in the maintenance of telomere integrity. Our data indicate that YRA1 overexpression correlates with replication impairment as inferred by the increase of Rrm3, a helicase involved in the replication fork progression, at transcribed genes and telomeres.
Project description:Transcription is a major obstacle for replication fork progression and a cause of genome instability. Yra1 is an essential nuclear factor of the evolutionarily conserved family of hnRNP-like export factors that when overexpressed impairs mRNA export and cell growth. Through this ChIP-chip analysis it is shown that Yra1 binds to active chromatin and is enriched at telomeres when it is overexpressed, in agreement with a possible role of this mRNP factor in the maintenance of telomere integrity. Our data indicate that YRA1 overexpression correlates with replication impairment as inferred by the increase of Rrm3, a helicase involved in the replication fork progression, at transcribed genes and telomeres. ChIP-chip studies were perfomed with antibodies against HA-tagged Yra1 protein in wild-type cells and cells overexpressing YRA1 of the yeast S. Cerevisiae, as well as Flag-tagged Rrm3 protein in both wild-type and cells overexpressing YRA1.
Project description:Transcription is a major obstacle for replication fork progression and a cause of genome instability. Such instability increases in mutants with a suboptimal assembly of the nascent messenger ribonucleo-protein particle (mRNP), as THO/TREX and the NPC-associated THSC/TREX-2 complex. Here we show that yeast sac3M-bM-^HM-^F and thp1M-bM-^HM-^F cells accumulate genome-wide replication obstacles as determined by the distribution of the Rrm3 helicase. Such obstacles preferentially occur at long and highly expressed genes, to which Sac3 and its interacting partner Thp1 are preferentially bound in wild-type cells. ChIP-chip studies were perfomed with antibodies against Flag-tagged Thp1 and Sac3 proteins in wild-type cells of the yeast S. Cerevisiae, as well as Flag-tagged Rrm3 protein in sac3M-bM-^HM-^F and thp1M-bM-^HM-^F cells that were compared with Rrm3 in wild-type cells from Santos-Pereira et al., 2013 (accession number GSE50185).
Project description:Transcription factor (TF) MYC binds to thousands of gene regulatory elements in the genome such as promoters and enhancers and exerts an amplification effect on the expression of most genes, regardless of the E-box motif existence. In this study, we discovered that MYC is an RNA-binding protein with a high affinity to guanosine-rich RNAs. RNAs that bind to MYC increase MYC’s chromatin occupancy, which helps with MYC-mediated regulation of gene expression. Mechanistically, two highly conserved sequences, amino acids 355-357 and 364-367, in the basic region of MYC are essential for RNA binding. Notably, alanine substitution of Lys355, Arg356, and Arg357 of MYC abolishes its RNA binding function but does not influence its complex formation ability, and E-box binding capacity of MYC:MAX dimer in vitro. However, loss of RNA binding function alone decreases MYC recruitment at gene regulatory elements in vivo, followed by a decreased MYC:MAX chromatin binding at these regions. This process further attenuates MYC-mediated gene expression. Therefore, RNA-binding-deficient MYC is compromised in promoting cancer cell proliferation. By demonstrating the mechanism of MYC-RNA interaction and the fundamental role of RNA binding activity in MYC-centric functions, our study reveals a new paradigm to MYC function and highlights an essential and probably general role of RNA binding capacity of TFs for their gene regulatory function.